Hi Dan,
Yes you are right , I think in my case pBuf has corrupted memory and while
trying to access this it
is crashing.
Regards,
Ashok
On Tue, Aug 20, 2013 at 7:47 PM, Dan Kennedy <danielk1...@gmail.com> wrote:
> On 08/20/2013 09:08 PM, Ashok Pitambar wrote:
>
>> Hi Richard,
>>
>> If list of available buffers (*db->lookaside.pFree*) is NULL
>> and
>>
>> it is assigned
>> to pBuf and if you access pBuf->pNext it will crash. read my comments in
>> below code
>> snippet.
>>
>> There is good chance that sqlite may end up with empty
>> lookaside pool(*db->lookaside.pFree*) list when there were many prepare
>>
>> statements are executed.
>>
>> please read my comments in code:
>>
>> if( db->lookaside.bEnabled ){
>> if( n>db->lookaside.sz ){
>> db->lookaside.anStat[1]++;
>> }
>> * //pBuf assigned with list of available buffers *
>> * else if( (pBuf = db->lookaside.pFree)==0 ){*
>>
>> db->lookaside.anStat[2]++;
>> }else{
>> * //it will crash here and there is no check for NULL here*
>> * db->lookaside.pFree = pBuf->pNext;*
>>
>> db->lookaside.nOut++;
>> db->lookaside.anStat[0]++;
>> if( db->lookaside.nOut>db->**lookaside.mxOut ){
>> db->lookaside.mxOut = db->lookaside.nOut;
>> }
>> return (void*)pBuf;
>>
>
> You're misreading the "else if" condition. If pBuf is set to NULL,
> the condition will be true and the "db->lookaside.anStat[2]++;"
> line executed. Not the block below it.
>
>
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